作者：Alex Wawro

明确如何设计玩家与VR游戏互动的方式是很困难的，特别是当现在市场上还没有多少高端VR耳机的时候。但在GDC Europe上，Valve的Yasser Malaika提醒开发者不仅应该将VR互动设计当成一种挑战，也应该将其当初是一种机遇。

VR(from ingdan)

Malaika说道：“互动是VR的必要元素，你必须让用户在与VR内容进行互动时感到满足。”但是开发者很少有机会去测试玩家是如何伸手去碰触他们的游戏。

我之所以说碰触是因为Malaika做出了这样的假设，即大多数VR开发者都是面向那些可以使用手势控制（如HTC Vive的掌上控制器）的玩家创造体验。

Malaika说道：“我们喜欢手动控制是因为我们认为这是一个不容易解决的谜题。我们认为对于所有消费者来说创造性是非常重要的，所以开发者才有自信去探索针对于VR的创新体验。”

但是并不存在标准化的VR输入方案：如今大多数玩家与VR游戏的互动都是通过头部运动，游戏手柄或掌上移动控制器完成的。Malaika认为VR输入技术的标准化是件好事，即使是在早期阶段—-它具有一些优势：玩家可以基于平稳的学习曲线从一款VR游戏转向另一款VR游戏，并且开发者将能够更轻松且有效地瞄准不同平台。

Malaika说道：“我们认为在早前阶段，开发者面向多个平台去开发游戏是很重要的。这能够缓解某些风险，并且能够更好地推动VR开发市场的发展。”

Malaika继续分享了Valve从VR互动设计中获得的经验教训，即不管是他们内部的尝试还是在与其他VR开发者的合作中。

不要越过河流

他给VR开发者的第一个建议便是改变你对于游戏设计的了解，即改变传统的输入习惯并明确真正适合VR的方法。通常游戏手柄中右边的控制杆是控制摄像机的移动，即将有效代理玩家的头部移动。当你在创造一款支持游戏手柄的VR游戏时，你最好让玩家能够通过头部移动去控制摄像机而赋予右边控制杆其它功能。

Malaika说道：“不要越过河流。”也就是说不去使用一些违反直觉的输入方法去混淆玩家。例如“映射指向或与玩家头部的互动不尽人意，而这将大大削弱用户所面对的自然管理任务。”

但有时候这种违反直觉的方法也是可行的。Malaika便分享了一个Valve工程师最初所创造让玩家通过移动头部穿梭于一个虚拟世界的演示版本。当工程师访问了运动控制器后，他们调整了演示版本让玩家通过摆动手臂进行移动，并最终证明这样的设定是有趣的。

Malaika说道：“这在一开始可能会有点奇怪，但这也是玩家能够快速适应的内容，随后他们便会忘记自己之前不适应的情况。”

抽象而非超现实

另一个经验教训便是来自创造玩家角色原型的时候，即抽象比真实有用。Malaika说道，Valve发现在那些尝试着创造真实感的游戏中，玩家的沉浸感远不如基于卡通感的游戏，例如Owlchemy Labs的《Job Simulator 2050》（游戏邦注：即Valve用于演示其Vive耳机的游戏）。

Malaika说道：“关于视觉效果和互动存在某种非常有趣的模型。它突出了在VR中，观察和游戏测试是不可取代的。”

当Valve在创造自己的Aperture Science VR演示版本时，Malaika表示该公司在投入许多精力去渲染尽可能真实的环境后遇到了许多困难。

Malaika说道：“我们投入了许多时间去强化物理真实感。我们拥有高像素的纹理，标准图，基于视差的环境地图等能够让界面显得更真实的内容。”但问题就在于所有额外的细节都比开发者在演示版本中添加的用于呈现可互动内容和静态内容的细小线索（如实验室抽屉锁小小的绿色和红色LED灯）重要，并会让玩家因为觉得自己将与不能互动的对象进行互动而紧张。

确保玩家能够做的所有事都是有意义的

Malaika同样也建议VR开发者该避免去渲染那些没有意义的姿势。例如你可以要求玩家伸出手去抓取一个门把手，并将其转90度去开门。Malaika说道：“尽管玩家一开始会觉得这很新奇，但是很快地他们便会觉得无聊了。”他的经验表明最好将这些复杂的细节留给那些主要任务。就像他说道：“我总是会问自己一个问题，即‘这是否有意义？’”

同时你也必须确保这是否值得玩家投入自己在游戏中的能力，即VR中的输入内容总是比传统主机游戏或PC游戏设计更有限，所以你必须考虑清楚每个输入内容是否有意义。

Malaika说道：“在VR中，你并没有一个拥有全键盘的热键。控制器上的按键非常有限，所以你必须考虑如何提供同等数量的选择并去管理用户所拥有的选择。”

注：如果你开发了一款面向Vive或其它VR系统且带有触觉反馈的游戏，Malaika建议你能够尝试一些较温和的触觉反馈。他说道，脉冲能够触发玩家的触感，并通过将虚拟刺激与他们的身体联系在一起而让他们更加沉浸于游戏中。

最后Malaika希望VR游戏开发者能在创造虚拟体验时始终牢记玩家的物理现实。他说道：“你应该带给玩家互动，但却不能将其反过来。”VR是根植于实体空间，所以在设计你的下一款VR游戏时你必须考虑像玩家重量，移动性以及他们玩游戏的空间等等元素。

（本文为游戏邦/gamerboom.com编译，拒绝任何不保留版权的转发，如需转载请联系：游戏邦）

Valve shares advice on designing great VR game interactions

By Alex Wawro

Figuring out how to design the ways players interact with your VR game is tricky business, especially now when many high-profile VR headsets haven’t even hit the market yet. But Valve’s Yasser Malaika cautioned developers at GDC Europe today to look upon VR interaction design as a challenge, but also as an opportunity..

“Interaction is turning out to be an essential part of VR, as a medium,” says Malaika. “It is profoundly satisfying for users to interact with [VR] content,” and developers have a rare opportunity to freely experiment with how players reach out and touch their games.

I say touch because Malaika spoke with the assumption that most VR developers will be making experiences for players that have access to gesture controls, like those afforded by HTC Vive’s handheld controllers.

“We favor hand controls because we feel like that’s a piece of the puzzle that wasn’t easily accessible,” says Malaika. “We feel its important for every customer to have that out of the box, so developers feel confident that they can explore VR-specific, novel experiences.”

But of course, there’s yet no standardized VR input scheme: right now, most players interact with VR games via either head movements, a gamepad or handheld motion controllers. Malaika suggests the standardization of VR input technology is a good thing, even at this early stage, and highlights several upsides: it’s easy for players to move from VR game to VR game with a minimal learning curve, and its easier for devs to target multiple platforms efficiently.

“We feel it’s very important, in these early days, for developers to develop for multiple platforms,” says Malaika. “We think that mitigates some of the risks, and we hope it will help the market for VR develop in a healthy way.”

Malaika went on to share some of the lessons Valve has learned about designing VR interactions, both from its own internal experiments and its partnerships with other VR developers.

Don’t cross the streams

His first piece of advice for VR developers to break down what you know about game design and “break out” traditional input conventions to figure out where they would most intuitively work in VR. The right stick on a gamepad typically controls camera movement, for example, effectively standing in for the player’s head movement. When you’re making a VR game that supports gamepads it makes more sense to let the player control their camera using head movement and bind the right stick to some other function.

“Don’t cross the streams,” says Malaika. In other words, don’t confuse your player by using unintuitive input methods. For example, “Mapping pointing or interaction with your head can be less than satisfactory….and doing so detracts from its natural task of governing what the user is looking at.”

Except sometimes, crossing the streams can actually work out okay. Malaika shared the example of a demo which the Valve engineers initially built to allow players to move through a virtual world by moving their head; when the engineers got access to motion controllers, they modified the demo to let the player move by waving their hand in a direction, and it turned out to be surprisingly enjoyable.

“It was sort of strange the first time, but it was one of those things you kind of quickly get used to, and then immediately miss when you don’t have,” says Malaika.

Go for abstract, not hyper-realistic

Another lesson learned was that when it comes to modeling player avatars in VR, abstract trumps the real. Malaika says Valve has found that players tend to feel less immersed in games that try to model hands realistically, and more immersed in games with cartoony hands — like in Owlchemy Labs’ Job Simulator 2050 (pictured), for example, which Valve has been using to demo its Vive headset.

“There’s a really kind of interesting matrix of representation of visuals and of interaction,” says Malaika. “It really highlights how, in VR, there’s no substitute for observing and play testing.”

When Valve was creating its own Aperture Science VR demo, Malaika says the company ran into difficulties after pouring a bunch of energy into rendering the environment as realistically as possible.

“We put a lot of time into trying to enhance the physical realism…we had high-res textures, normal maps, parallax-sensitive environment maps…all of those things really helped to make the surfaces feel tangible,” says Malaika. Problem was, all that extra detail outshone the tiny clues the developers had seeded in the demo to show which objects were interactable and which were static — small green and red LED lights on lab drawers, for example — and wound up disappointing players by making them think they could interact with things they couldn’t.

Make sure everything a player can do is meaningful

Malaika also recommends that VR developers avoid the temptation to render unmeaningful gestures in great detail. For example, you can require players to reach out, grasp a door handle, and turn it a full 90 degrees to open a door. “Something like that, although novel the first time, can quickly become fatiguing,” says Malaika. His experience suggests its probably best to save those levels of intricate detail for critical tasks. “I like to ask myself the question, ‘Is this meaningful?’”

The same goes for affording your player in-game abilities — input in VR is much more limited than traditional console or PC game design, so you have to thnk very carefully about whether each input is meaningful.

“In VR, you don’t have a keyboard full of hotkeys,” says Malaika. “The buttons on a controller are much more limited, so you have to think about how to provide the same number of choices…and manage the number of choices a user has.”

Quick note: If you happen to be developing a game for the Vive or another VR system with haptic feedback, Malaika recommends experimenting with gentle haptics. Pulses can trigger a player’s sense of touch, he says, and more deeply immerse them in your game by linking a virtual stimulus with their real body.

Finally, Malaika reminds fellow VR game developers to try and keep a player’s physical realities in mind when crafting virtual experiences. “Bring interaction to the user, not vice versa,” says Malaika; VR is heavily rooted in physical space, and so you have to consider things like a player’s height, their mobility (or lack thereof) and the room they’ll be playing in when designing your next VR game.（source：Gamasutra）